Air-distance indicator for aircraft



M. M. TITTERINGTON'.

AIR DISTANCE INDICATOR FOR AIRCRAFT.

APPLICATION FILED SE PT. [4. I918.

Patented Feb. 8, 1921.

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UNITED, STATES PATENT OFFICE.

MORRIS 1K. TITTERINGTON, 0F BROOKLYN, EW YORK, .ASSIGNOR TO THE SPEBR'Y GYROSCOPE COMPANY, OF BROOKLYN, NEW -YORK, A'CORPORATION OF NEW roan.v

un msrmncn-mmca'roa ron AIRCRAFT.

Specification of Letters Patent.

Patented Feb. 8, 1921.

Application filed September 14, 1918. .serial No. 254,097.

To all whom "it-may concern Be it known that I, Mortars M. T rr'rnR- iNeroN, a citizen of the United States of America, residing at Brooklyn, in the county of Kings and State of NewYor'k,

have invented certainnew and useful Improvements in Air-Distance lndicators' -for Aircraft, of which the following is a spec fication.

relative distance traveled by the aircraft through the air.

The term air distance is used through-' out the specification and claims herein as an apt expression for the relative movement of the 'aircraftand the air through which the aircraft is traveling.

The principal object of the invention -is to provide an instrument in which the wind actuated member may be placed in an ad- .vantageous position upon the craft while the readingor indicating member is located in a position convenient'tothe pilot.

Other, objects will appear in the description which follows. a 1

Referring to the drawings wherein I have shown what- I now consider to be the pre- I ferred form of my invention:

' Figure 1 '1s a sectionalside elevation of the wind actuated portion of the instrument, including the controlling. mechanism for the indicating'm'ember.

Fig. 2 is a view of the indicating member. Fig. 3 is a sectional view of the means for actuating the indicating member.

Fig. 4 is a fragmentary view of an aeroplane showing thein'anner in which my invention may be applied. v

' In Fig. 4 the wind actuated or respon sive member is shown as comprising a wind wheel 1 mounted on the front end of a' casing 2 which is attached by means of a tube 3 and clamping means 4 to one of the forward struts 5 of the flying craft 6, while the indicator 31 is -shownas mounted on the instrument board40, withv a tubing or other means" 38 connecting-the two members.

' In Fig. 1 the wind wheel 1 is shown as [comprising fan blades 7 radially attached to the rim18 of a wheel having a hub 9. The. said hub is 'shovvnas mountedupon a shaft:

of a chain of reduction gears 15 mounted in a frame or the like 22. The last gear 16 of said train may be provided with aplurality of pegs 17 in one side thereof. As stated, it is of course preferable to mount the wind wheel on some portion of the aircraft where the wind has a free sweep and at a suflicient distance from the propeller not to be influenced thereby. In such posi-v tion, of course,'readings of the instrument cannot be seen by the aviator. It is therefore desirable to transmit readings of the instrument to-the' dashboard. For this purpose it is obvious that the 'ordinar transmitting means, such as used in eye ometers for wheeledjvehicles, in which a pin on a wheel strikes 'a' starwheel, or the like each revolution, would be inoperative as any mechanism which places sudden and intermlttent loads on the fan would affect the accuracy of the same or cause the same to stick.

By my invention, however, I have provided a novel 'fluid pressure transmitting means in which the mlnimum load is laced upon the wheel, said load being, in addition,

substantially uniform although variable pressure impulses are sent out by the transmitter to the indicator on the dash.

' The rear end of casing 2is shown as contaming anair compressor 18, com rising a piston casing-19 and a piston 20, aving apiston rod 21 extending out through one end of said casing. A compression spring 23 maybe provided butting at one end 23 against one end of the piston casing, and at .the other end 23 against the piston 20. for

normally holding said istonin its closed position as shown. Pre erably, a slot 24 is provided in the side of casing 19 through which a screw or the like 25 secured inthe piston may pass, to prevent relative rotation of the piston within the casing.

arm :8 is shown pivotally secured as uter end of piston rod 21. The of said arm may be hook shaped as at '26, and may be positioned so as to lie in the path of pegs 17 carried by the rotating disk or gear 16. Suitable provision may be made to hold arm :26 resiliently against pegs 17. For this purpose arm as may assume the form of a bell crank lever by the provision of anadditional arm 26 having a tension spring .28 attached to its upper end and to screw 25. As disk 16 rotates in the direction indicated by arrow 29, pegs 17 will engage hook 26 as shown. Continued rotation of said disk will then more arm 26 into the dotted line position 30. Thus piston :20 will be pulled against the compression of spring 23.

ll hile arm 26'is being moved into dotted line position 30, the next peg 17 following will engage thet-op of said arm and grad ually press it out of engagement with the peg ahead. is soon as the hook is thus re leased. spring 23 will thrust the piston back position shown and the arm 26 back ull line position where the hook is i en aged by the 116263 peg as shown and the foregoing steps repeated.

The. indicating member of the instrument is shown at 31 in Fig. 2. The mechanism of this member may be. that of any of the well known counting devices and is therefore not shown here; it being suiiicient to state that the actuation of the device is effected by a partial rotation of lever arm 32 secured on the shaft 33 of the device, (see also Fig. 3). This arm is shown as bifurcated and engages between its projections, a pin 34- fixed in a cylinder or transmitting element 35 in the cylinder casing 36; the pin projecting without the casing as shown in.- Fig. 2 through a slot not shown, similar to slot 24- shown in the piston casing 19 in Fig.

1. A spring 37 is provided to normally maintain cylinder 35 in the position. shown.

When piston '20 (Fig. 1) is pulled forward against spring 23 which takes place slowly, thus placing a very small and substantially uniform load on the fan, air leaks through between the piston and casing into the chamber thus created in the rear end of casing 19. But when the piston is thrustback by said spring more rapidly than the air can escape through the same space, it is forced through tubing or conduit 38 into c linder casing 36, between the end 36 hereof and cylinder 35. This thrusts cylinder- 35 backward against spring 37, and e'f fects the aforementioned partial rotation of lever arm 32, and actuates the indicating device. lit will, therefore, be evident that no air is compressed by the direct action of the wind wheel.

As shown in Fig. 1, I may provide one or more grooves 39 around the bearing surface of piston :20. The groove may incline gradually from said bearing surface to convenient depth; the shallower side being toward the air compression end of the pis ton. The groove will thus effect the formation of an oil ring 42 of the lubricating oil between the piston and casing during the compression stroke, and a spreading of said oil during the receding stroke. This .will aid in preventing the escape of air around the piston during the air compression stroke, while permitting the leaking in of air dur ing the receding stroke.

In accordance with the provisions of the patent statutes, l have herein described the principle of operation of my invention. together with the apparatus, which I now consider to represent the best embodiment thereof, but I desire to have it understood that the apparatus shown is only illustrative and that the invention can be carried out by other means. Also, while it is designed to use the various features and ele ments in the combination and relations described, some of these may be altered and to bring into action said means and adapted to be located on an exposed portion of the craft.

2. An indicating instrument for aircraft comprising a wind driven fan, a cigarshaped casing rotatably supporting said fan at its forward end and adapted to be secured to an exposed portion of the airplane, reduction gearing within said casing, a fluid pressure varying means actuated thereby, a remotely located indicating device, pressure responsive means for actuating the' same, and a connectionbetween said casing and said indicator.

3. An indicating instrument 'for aircraft comprising a substantially cylindrical casing having rearwardly extending reduced member adapted to be secured to the airplane a revoluble nose on said casing, blades or vanes secured to said nose, reduction gearing within said casing rotated by said nose, and a transmitting means also within said casing for transmitting. to a distance intermittent impulses inproportion to the number of revolutions of said nose.

4. An indicating instrument for aircraft comprising a wind driven. fan, afiuid pressure varying device adapted to transmit intermittent impulses, and means substantially uniformly actuated by said'fan for bringing into action said pressure varying means. I

5. An indicatin instrument for aircraft comprising a win driven fan, a fluid pressure-varying device adapted to transmit intermittent impulses, and means brought into action by the rotation of said fan which energizes slowly and releases suddenly said pressure varying means. I

6. An indicating instrument for aircraft comprising a wind driven fan, and a fluid pressure varying device controlled thereby and adapted to transmit intermittent impulses, comprising means adapted normally to cause only slight reduction of pressure in said device but to cause periodically sudden larger variations in pressure in proportion to the revolutions of the wind wheel.

7 An indicating instrument for aircraft comprising a substantially cylindrical casing, a forwardly revoluble nose on said casing, blades or vanes'secured to said nose, I re u within said casing for transmitting to a distance intermittent impulses in proportion to the number of revolutions of said nose.

8. An indicating instrument for aircraft comprising a wind driven fan, reduction gearing connected thereto, a member rotated thereby, means brought into action periodically by the rotation of said member. and adapted to causeperiodic, sudden variations in fluid pressure, and an indicator actuated by such variations in fluid pressure.

9. An air distance indicating instrument for aircraft comprising a wind driven fan adapted to be located on an exposed portion of the airplane and actuated by the forward travel of the aircraft, a transmitting means driven by said fan, a totalizing device adapted to be located adjacent the aviator, motive means for actuating said totalizing device, and means interconnecting said transmitting means and motive means for actuating the latter from the former.

In testimony whereof I have aflixed my signature.

MORRIS M. TITTERINGTON. 

